public class Example3_1 {
	public static void main (String args[]) {
	  char a1 = '十',a2 = '点',a3 = '进',a4 = '攻';
	  char secret = 'A';
	  a1 = (char)(a1^secret);
	  a2 = (char)(a2^secret);
	  a3 = (char)(a3^secret);
	  a4 = (char)(a4^secret);
	  System.out.println("密文:"+a1+a2+a3+a4);
	  a1 = (char)(a1^secret);
	  a2 = (char)(a2^secret);
	  a3 = (char)(a3^secret);
	  a4 = (char)(a4^secret);
	  System.out.println("明文:"+a1+a2+a3+a4);
	}
}